The present invention relates to an image pick-up device for transforming with a television (TV) camera an optical image representative of a document, figure, photo, OHP (Over Head Projector) film, model or similar subject laid on a stage to a video signal, and reproducing the image represented by the video signal on a screen in a conference room or on the individual monitor in a communication conference.
A conventional image pick-up device for the above application has a stage to be loaded with a subject, a TV camera having a lens for shooting the subject, a light source unit having a lens for illuminating the subject, optics including at least two mirrors for conducting an optical image representative of the subject to the camera, and posts supporting the light source unit and camera.
The image pick-up device having the above construction has various problems left unsolved, as enumerated below.
(1) Part of the light issuing from the light source unit is apt to leak to the outside of the stage and appear on a screen or a monitor, thereby blurring the image. PA1 (2) Shadows appear in the image on the screen or the monitor and prevent the image from being clear-cut. PA1 (3) The camera is awkward to operate. PA1 (4) The posts arranged around the stage obstruct, e.g., the replacement of the subject. PA1 (5) Heat generated by the light source unit deteriorates the working environment. PA1 (6) The lens of the camera and the lens of the light source unit are expensive, increasing the production cost of the entire device. PA1 (7) The optical axis of the lens of the light source unit and that of the lens of the camera cannot be easily brought into coincidence, resulting in time- and labor-consuming adjustment. PA1 (8) The illumination on the subject is irregular due to the irregular light distribution particular to the light source unit and the shading of the camera, so that the quality of the output image is limited.